'''Piano Sonata No. 15 in F major''', KV 533/494 (finished January 3 1788) is a sonata in three movements:
A typical performance takes about 23 minutes.
The Rondo was originally a stand-alone piece composed by Mozart in 1786 ('''Rondo No. 2''', K. 494 in the Köchel catalogue). In 1788, Mozart wrote the first two movements of K. 533 and incorporated a revised version of K. 494 as the finale, having lengthened it in order to provide a more substantial counterpart to the other two movements.[http://www.classicalarchives.com/work/18367.html#tvf=tracks&tv=about All Music Guide]